Genetical exchanges between one Biomphalaria glabrata (Gastropoda: Planorbidae) and a varying number of partners

When one pigmented Biomphalaria glabrata is mated with 1 to 20 albino snails, the percentage of albino parent producing pigmented offspring decreases while the percentage of parent laying albino offspring increases. If the number of snaisl/group increases, the mean duration of the use of allosperm decreases.

Readiness to participate in psychiatric research.

BACKGROUND: The feasibility of clinical trials depends, among other factors, on the number of eligible patients, the recruitment process, and the readiness of patients to participate in research. Seeking patients' views about their experience in research projects may allow investigators to develop more effective recruitment and retention strategies. METHODS: A total of 100 patients consecutively admitted to a psychiatric university hospital were interviewed with respect to their willingness to participate in a study. For a different study scenario, patients were asked whether they would be ready to participate if such a study were organized in the service and to indicate their reasons for refusing or for participating. RESULTS: The general readiness to participate in a study ranged between 70% and 96%. The prospect of remuneration did not notably augment the potential consent rate. The most common and spontaneous motivation for agreeing to take part in a study was to help science progress and to allow future patients to benefit from improved diagnosis and treatment (87%). The presence or lack of a financial incentive was rarely chosen as an argument to agree (23%) or to refuse (7%) to participate. Patients relied mainly on their treating physicians when contemplating possible participation in a study (family physician [65%] and hospital physician [54%]). CONCLUSIONS: Clinicians and, in particular, treating doctors can play an important role in facilitating the recruitment process.

Promoting hospital-based smoking cessation services at major Swiss hospitals: a before and after study.

Whether a 1-year nationwide, government supported programme is effective in significantly increasing the number of smoking cessation clinics at major Swiss hospitals as well as providing basic training for the staff running them. We conducted a baseline evaluation of hospital services for smoking cessation, hypertension, and obesity by web search and telephone contact followed by personal visits between October 2005 and January 2006 of 44 major public hospitals in the 26 cantons of Switzerland; we compared the number of active smoking cessation services and trained personnel between baseline to 1 year after starting the programme including a training workshop for doctors and nurses from all hospitals as well as two further follow-up visits. At base line 9 (21%) hospitals had active smoking cessation services, whereas 43 (98%) and 42 (96%) offered medical services for hypertension and obesity respectively. Hospital directors and heads of Internal Medicine of 43 hospitals were interested in offering some form of help to smokers provided they received outside support, primarily funding to get started or to continue. At two identical workshops, 100 health professionals (27 in Lausanne, 73 in Zurich) were trained for one day. After the programme, 22 (50%) hospitals had an active smoking cessation service staffed with at least 1 trained doctor and 1 nurse. A one-year, government-supported national intervention resulted in a substantial increase in the number of hospitals allocating trained staff and offering smoking cessation services to smokers. Compared to the offer for hypertension and obesity this offer is still insufficient.

Which screening strategy using BMD measurements would be most cost effective for hip fracture prevention in elderly women? A decision analysis based on a Markov model.

INTRODUCTION: Hip fractures are responsible for excessive mortality, decreasing the 5-year survival rate by about 20%. From an economic perspective, they represent a major source of expense, with direct costs in hospitalization, rehabilitation, and institutionalization. The incidence rate sharply increases after the age of 70, but it can be reduced in women aged 70-80 years by therapeutic interventions. Recent analyses suggest that the most efficient strategy is to implement such interventions in women at the age of 70 years. As several guidelines recommend bone mineral density (BMD) screening of postmenopausal women with clinical risk factors, our objective was to assess the cost-effectiveness of two screening strategies applied to elderly women aged 70 years and older. METHODS: A cost-effectiveness analysis was performed using decision-tree analysis and a Markov model. Two alternative strategies, one measuring BMD of all women, and one measuring BMD only of those having at least one risk factor, were compared with the reference strategy "no screening". Cost-effectiveness ratios were measured as cost per year gained without hip fracture. Most probabilities were based on data observed in EPIDOS, SEMOF and OFELY cohorts. RESULTS: In this model, which is mostly based on observed data, the strategy "screen all" was more cost effective than "screen women at risk." For one woman screened at the age of 70 and followed for 10 years, the incremental (additional) cost-effectiveness ratio of these two strategies compared with the reference was 4,235 euros and 8,290 euros, respectively. CONCLUSION: The results of this model, under the assumptions described in the paper, suggest that in women aged 70-80 years, screening all women with dual-energy X-ray absorptiometry (DXA) would be more effective than no screening or screening only women with at least one risk factor. Cost-effectiveness studies based on decision-analysis trees maybe useful tools for helping decision makers, and further models based on different assumptions should be performed to improve the level of evidence on cost-effectiveness ratios of the usual screening strategies for osteoporosis.

Phenotypic consequences of copy number variation: insights from Smith-Magenis and Potocki-Lupski syndrome mouse models.

A large fraction of genome variation between individuals is comprised of submicroscopic copy number variation of genomic DNA segments. We assessed the relative contribution of structural changes and gene dosage alterations on phenotypic outcomes with mouse models of Smith-Magenis and Potocki-Lupski syndromes. We phenotyped mice with 1n (Deletion/+), 2n (+/+), 3n (Duplication/+), and balanced 2n compound heterozygous (Deletion/Duplication) copies of the same region. Parallel to the observations made in humans, such variation in gene copy number was sufficient to generate phenotypic consequences: in a number of cases diametrically opposing phenotypes were associated with gain versus loss of gene content. Surprisingly, some neurobehavioral traits were not rescued by restoration of the normal gene copy number. Transcriptome profiling showed that a highly significant propensity of transcriptional changes map to the engineered interval in the five assessed tissues. A statistically significant overrepresentation of the genes mapping to the entire length of the engineered chromosome was also found in the top-ranked differentially expressed genes in the mice containing rearranged chromosomes, regardless of the nature of the rearrangement, an observation robust across different cell lineages of the central nervous system. Our data indicate that a structural change at a given position of the human genome may affect not only locus and adjacent gene expression but also "genome regulation." Furthermore, structural change can cause the same perturbation in particular pathways regardless of gene dosage. Thus, the presence of a genomic structural change, as well as gene dosage imbalance, contributes to the ultimate phenotype.

Morphologie et reproduction des plantes le long de gradients altitudinaux.

Les communautés végétales sont connues pour changer avec l'altitude. Certains traits morphologiques présents chez les végétaux qui les composent sont adaptés à un type de milieux et y sont représentés préférentiellement. Dans cette étude, nous nous sommes intéressés à la variation des traits présents chez les plantes le long du gradient altitudinal. Nous avons ainsi étudié dix transects altitudinaux en milieux ouverts et en forêts dans les Alpes valaisannes, vaudoises et dans le Jura. Par ce biais, nous avons pu mettre en évidence une variation importance de la dominance de certains traits le long de l'altitude. Nous discutons les mécanismes évolutifs ayant modelés les motifs observés.

Privatization and competition in the delivery of local services: An empirical examination of the dual market hypothesis

This paper empirically analyses the hypothesis of the existence of a dual market for contracts in local services. Large firms that operate on a national basis control the contracts for delivery in the most populated and/or urban municipalities, whereas small firms that operate at a local level have the contracts in the least populated and/or rural municipalities. The dual market implies the high concentration and dominance of major firms in large municipalities, and local monopolies in the smaller ones. This market structure is harmful to competition for the market as the effective number of competitors is low across all municipalities. Thus, it damages the likelihood of obtaining cost savings from privatization.

An alteration in the levels of populations of CD4+ Treg is in part responsible for altered cytokine production by cells of aged mice which follows injection with a fetal liver extract.

We have shown previously that a fetal sheep liver extract (FSLE) containing significant quantities of fetal ovine gamma globin chain (Hbgamma) and LPS injected into aged (>20 months) mice could reverse the altered polarization (increased IL-4 and IL-10 with decreased IL-2 and IFNgamma) in cytokine production seen from ConA stimulated lymphoid cells of those mice. The mechanism(s) behind this change in cytokine production were not previously investigated. We report below that aged mice show a >60% decline in numbers and suppressive function of both CD4(+)CD25(+)Foxp3(+) Treg and so-called Tr3 (CD4(+)TGFbeta(+)), and that their number/function is restored to levels seen in control (8-week-old) mice by FSLE. In addition, on a per cell basis, CD4(+)CD25(-)Treg from aged mice were >4-fold more effective in suppression of proliferation and IL-2 production from ConA-activated lymphoid cells of a pool of CD4(+)CD25(-)T cells from 8-week-old mice than similar cells from young animals, and this suppression by CD25(-)T cells was also ameliorated following FSLE treatment. Infusion of anti-TGFbeta and anti-IL-10 antibodies in vivo altered Treg development following FSLE treatment, and attenuated FSLE-induced alterations in cytokine production profiles.

Self-fertilization in the freshwater snails Helisoma duryi and Helisoma trivolvis

Fifty specimens of five strains (10 per strain) of Helisoma duryi from Lima (Peru), St. Croix (Virgin Islands), Formosa (Brazil), Cartago (Costa Rica) and St. Vincent (Lesser Antilles), reared in isolation for about 150 days, laid 103 eggs. The numbers of eggs laid by the 10 specimens of each strain were respectively (viable eggs in parenthesis): 44(26), 1 (1), 5(0), 15 (7) and 38 (0). Egg production widely varied between the individuals of each strain, there being in all strains,except St. Vincent, a number of specimens (3 to 9) which did not lay any eggs. After the observation period the isolated specimens, including those that laid no eggs, readily engaged in cross-breeding when mated and brought forfh large numbers of eggs. Self-fertilized F 1s are fully interfertile, producing normal cross-fertilized offspring. Ten specimens of Helisoma trivolvis (strain from Zempoala, Mexico), also reared in isolation for about 120 days, laid 646 eggs, of which 74 were inviable. our data, added to those from a few ´revious studies cited in the text, show that self-fertilization is not so efficient an alternative mode of reproduction in H. duryi as in many other planorbids (it is a little more efficient in H. trivolvis than in H. duryi). Thus, H. duryi benefits much less from functional hermaphroditism which, besides other advantages, enables a single virgin individual to found a new population.

Menarche, menopause, and breast cancer risk: individual participant meta-analysis, including 118 964 women with breast cancer from 117 epidemiological studies.

BACKGROUND: Menarche and menopause mark the onset and cessation, respectively, of ovarian activity associated with reproduction, and affect breast cancer risk. Our aim was to assess the strengths of their effects and determine whether they depend on characteristics of the tumours or the affected women. METHODS: Individual data from 117 epidemiological studies, including 118 964 women with invasive breast cancer and 306 091 without the disease, none of whom had used menopausal hormone therapy, were included in the analyses. We calculated adjusted relative risks (RRs) associated with menarche and menopause for breast cancer overall, and by tumour histology and by oestrogen receptor expression. FINDINGS: Breast cancer risk increased by a factor of 1·050 (95% CI 1·044-1·057; p<0·0001) for every year younger at menarche, and independently by a smaller amount (1·029, 1·025-1·032; p<0·0001), for every year older at menopause. Premenopausal women had a greater risk of breast cancer than postmenopausal women of an identical age (RR at age 45-54 years 1·43, 1·33-1·52, p<0·001). All three of these associations were attenuated by increasing adiposity among postmenopausal women, but did not vary materially by women's year of birth, ethnic origin, childbearing history, smoking, alcohol consumption, or hormonal contraceptive use. All three associations were stronger for lobular than for ductal tumours (p<0·006 for each comparison). The effect of menopause in women of an identical age and trends by age at menopause were stronger for oestrogen receptor-positive disease than for oestrogen receptor-negative disease (p<0·01 for both comparisons). INTERPRETATION: The effects of menarche and menopause on breast cancer risk might not be acting merely by lengthening women's total number of reproductive years. Endogenous ovarian hormones are more relevant for oestrogen receptor-positive disease than for oestrogen receptor-negative disease and for lobular than for ductal tumours. FUNDING: Cancer Research UK.

Experimental investigation of transient natural convection cooling of high prandtl number fluid with variable viscosity

Report for the scientific sojourn at the James Cook University, Australia, between June to December 2007. Free convection in enclosed spaces is found widely in natural and industrial systems. It is a topic of primary interest because in many systems it provides the largest resistance to the heat transfer in comparison with other heat transfer modes. In such systems the convection is driven by a density gradient within the fluid, which, usually, is produced by a temperature difference between the fluid and surrounding walls. In the oil industry, the oil, which has High Prandtl, usually is stored and transported in large tanks at temperatures high enough to keep its viscosity and, thus the pumping requirements, to a reasonable level. A temperature difference between the fluid and the walls of the container may give rise to the unsteady buoyancy force and hence the unsteady natural convection. In the initial period of cooling the natural convection regime dominates over the conduction contribution. As the oil cools down it typically becomes more viscous and this increase of viscosity inhibits the convection. At this point the oil viscosity becomes very large and unloading of the tank becomes very difficult. For this reason it is of primary interest to be able to predict the cooling rate of the oil. The general objective of this work is to develop and validate a simulation tool able to predict the cooling rates of high Prandtl fluid considering the variable viscosity effects.

Indicators for the total number of melanocytic naevi : an adjunct for screening campaigns. Observational study on 292 patients.

BACKGROUND: The presence of multiple melanocytic naevi is a strong risk factor for melanoma. Use of the whole body naevus count to identify at-risk patients is impractical. OBJECTIVES: To (i) identify a valid anatomical predictor of total naevus count; (ii) determine the number of naevi that most accurately predict total naevus count above 25, 50 and 100; and (iii) evaluate determinants of multiple melanocytic naevi and atypical naevi. METHODS: Clinical data from 292 consecutive Spanish patients consulting for skin lesions requiring debriding were collected throughout 2009 and 2010. Correlations between site-specific and whole body naevus counts were analysed. Cut-offs to predict total naevus counts were determined using the area under the receiver operating characteristic curve. RESULTS: The studied population was young (median age 31 years, interquartile range 28-43). The naevus count on the right arm correlated best with the total nevus count (R(2) 0·80 for men, 0·86 for women). Presence of at least five naevi on the right arm was the strongest determinant of a total naevus count above 50 [odds ratio (OR) 34·4, 95% confidence interval (CI) 13·9-85·0] and of having at least one atypical naevus (OR 5·7, 95% CI 2·4-13·5). Cut-off values of 6, 8 and 11 naevi on the right arm best predicted total naevus count above 25, 50 and 100, respectively. CONCLUSIONS: Our results support the arm as a practical and reliable site to estimate the total naevus count when screening or phenotyping large populations. Threshold values for the number of naevi on the arm are proposed to help identify patients for melanoma screening.